public class PhoneBook {
    private String _id;
    private double mobi;
    private UserInfo info;
 
    public class UserInfo {
        private String firstName;
        private String lastName;
        private int age;
 
        public String getFirstName() {
            return firstName;
        }
 
        public void setFirstName(String firstName) {
            this.firstName = firstName;
        }
 
        public String getLastName() {
            return lastName;
        }
 
        public void setLastName(String lastName) {
            this.lastName = lastName;
        }
 
        public int getAge() {
            return age;
        }
 
        public void setAge(int age) {
            this.age = age;
        }
 
    }
 
    public double getMobi() {
        return mobi;
    }
 
    public void setMobi(double mobi) {
        this.mobi = mobi;
    }
 
    public UserInfo getInfo() {
        return info;
    }
 
    public void setInfo(UserInfo info) {
        this.info = info;
    }
 
    public void setId(String _id) {
        this._id = _id;
    }
 
    public String getId() {
        return _id;
    }
 
    @Override
    public String toString() {
        return String.format("_id: %s \nmobi: %.0f \nuser.first_name: %s\nuser.last_name: %s\nuser.age: %d",
                getId(), getMobi(), getInfo().getFirstName(), getInfo().getLastName(), getInfo().getAge());
    }
 
 
}